NPB_EST.1979 wrote:Here are the reasons I can come up with:
Using one guitar throughout an entire setlist is taxing on the guitar. They wear out a lot faster, need refretting, and finish wears off at a much greater pace. Look at Stevie Ray's #1 for an example. BB King has a bout a million Lucille guitars.
Different guitars give a different mood. I think Joe calls them "moments" like when he plays the double-neck SG for YoungManBlues, etc. Sometimes I forget a riff I came up with, and go back to the guitar I wrote it on, and it comes back.
Different guitars have some different tones. LesPaul vs. Tele sort of thing. Like playing Mountain Time on a Gigliotti just sounds right. Billy Gibbons, on the other hand, has all his guitars sound like LesPauls. 
It's a show. People like to 'ooh and aah' at the fine collection of guitars. It's probably the closest most of us will ever get to a 1959 Les Paul. When a double-neck comes out... people gasp - and it's a story people bring home "and then he got out the doubleneck sg!"
Different tuning. John Henry, takin a hit, etc. have alternate tunings. Guitars in 440A can go out of tune as well, so switching out for ones in tune keeps the show going.
Gimme Back My BULLettes! Excellent reply of the the kind promoted in this section; EDUCATIONAL. TFSpaniel, stupid is adds stupid done. PLEASE remember there is no such thing as a stupid question. GO ahead and change edit your topic title! Curious Question now that is better.
People like Nic are HAPPY to share...right Nic?!
Rock ON & Keep the Faith,
Rocket
The guy is sharp 
"He still doesn't charge for mistakes!

"
http://jbonamassa.com/tour-dates/"Everybody wants ta get inta the act!"
“Now, this isn’t your ordinary party crowd, here. I mean, there are professionals in here.”